Right. I’ve had a lot of these for a while, but I’ve only now caught my breath after having twins and moving house (in 2010...ahem) to start looking at them properly. First off is my Mac II upgraded to a IIfx. I don’t think this is very healthy.
@elbaroni I used to be in the same boat as you not too long ago. This is what I've come to understand about recapping and capacitors: capacitance is what matters: the µf (microfarads) part. So you want to make sure that one is equal to what you need. The Voltage part is the rated tolerance. This one can be equal to or greater than what you need. So it's OK to put in a higher rated capacitor such as 47µf 20V in place of a 47µf 16V.
ESR isn't specified because it probably doesn't matter too much in this case. From what I've read, the lower the better.
Next is to just make sure that it's the right type of cap. Tantalums are good replacements for surface-mount caps. Axials are for a couple of the horizontal through-hole caps, and radials for the regular through-holes.
I just can't remember the type of capacitor, but there's one that LOOKS like an old electrolytic surface mount, but they're more reliable. They're also more expensive, but they'll keep the old-school look of the motherboard without using tantalums.
I think the ESR only really matters when you're dealing with heat-sensitive stuff. According to the Googles, the lower the ESR, the lower the amount of energy is dissipated as heat. So I would imagine that would make a difference if you're trying to make an efficient power supply and keep the heat levels down. Or if a device operating in a temperature controlled environment. That kind of stuff.
This has been a good morning. A LaserWriter I, a LaserWriter IIf, a LaserWriter IIg, and a 13inch trinitron monitor.
The seller (near Bathurst in Australia, so not much use to most of you) has a massive array of apple stuff - at least four SE/30s with Ethernet cards, at least six complete Mac plusses, LC580s, apple IIes with monitors, PowerMac 6100, 5400ish, image writer IIs including one sheet feeder, several Inagewriter Is and a LaserWriter IIntx. All in a decrepit old house that’s being renovated. No power, so can’t test, but certainly worth checking out.
Finally got to trying the LaserWriter IIs. The IIg has the two red flashing lights which the service book tells me means new laser assembly. The IIf boots fine, shows up on a network, and prints...kinda...but with some paper feed issues.
And finally got to the Laserwriter I. Don’t know yet if it’s a plain I or a plus (or what version of the plus) but it looks super clean inside apart from one spider corpse. I’ve ordered a new toner cartridge because the foam on the old one has liquidated. Turned it on and it made all the right noises, identified correctly that there’s no paper (although there is a paper tray!), but I turned it off before the green light stopped flashing. Dunno about that serial port though. Still, found a db9 appletalk kit for $5 which is cool. It and the toner are en route.